package jdbc;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class JDBCDemo7 {
    public static void main(String[] args) {
        try (
                Connection conn = DBUtil.getConnection();
        ) {
            Statement stmt=conn.createStatement();
            String sql="SELECT COUNT(*) count " +
                    "FROM student s,class c " +
                    "WHERE s.class_id=c.id " +
                    "AND c.name='1年级1班'";

            ResultSet rs=stmt.executeQuery(sql);
            if(rs.next()){
                int count=rs.getInt("count");
                System.out.println("1年级1班共有"+count+"人");
            }


        } catch (SQLException e) {
            e.printStackTrace();
        }

    }
}
